Answer:
she must increase the current by factor of 7
Explanation:
The magnetic field produced by a steady current flowing in a very long straight wire encircles the wire.In order to solve the question, we use this formula,
B= μo I/(2πr)
where,
'μo' represents permeability of free space i.e 4π*10-7 N/A2
B=magnetic field
I= current
r=radius
->When r= 1cm=> 0.01m
B1 = μo 
/(2π x 0.01)
->when r=7cm =>0.07m
B2 = μo 
/(2π x 0.07)
Now equating both of the magnetic fields, we have
B1= B2
μo /(2π x 0.01)= μo /(2π x 0.07)
/ = 0.01/0.07
/ = 1/ 7
Therefore, she must increase the current by factor of 7
Answer:
Answer explained below
Explanation:
(a) The rays are diverging near the lens. They change the direction when they passed through the converging lens
(b) If the light rays don't bend they will move away from the optical (principal axis) as the other waves are moving.
(c) If we decrease the distance between lens and light source, most of the rays diverge and no ray converges on the screen even after passing through the lens. Here is a screenshot.
Answer:
19.3m/s
Explanation:
Use third equation of motion
where v is the velocity at halfway, u is the initial velocity, g is gravity (9.81m/s^2) and h is the height at which you'd want to find the velocity
insert values to get answer
![v^2-0^2=2(9.81m/s^2)(38/2)\\v^2=9.81m/s^2 *38\\v^2=372.78\\v=\sqrt[]{372.78} \\v=19.3m/s](https://tex.z-dn.net/?f=v%5E2-0%5E2%3D2%289.81m%2Fs%5E2%29%2838%2F2%29%5C%5Cv%5E2%3D9.81m%2Fs%5E2%20%2A38%5C%5Cv%5E2%3D372.78%5C%5Cv%3D%5Csqrt%5B%5D%7B372.78%7D%20%5C%5Cv%3D19.3m%2Fs)
